can't find tach wire in '07 express

I am having the hardest time finding a Tach wire in my '07 Chevy Express.  The information from Audiovox says it's a white wire in a black connector near the drivers shock tower.  I checked the white wire in that connector and it is not the tach.  Can anyone tell me exactly where to pick up the tach in this vehicle??

Thanks,

Tom M

It sucks     @ the PCM under the hood, drivers side fenderwell

BROWN / white, blue plug pin #73

Awsome, I'll check it out tomorrow!  Thanks for the help.

Tom

Twelvoltz, good call.

That would be the coolest way of doing the job.... cause as I stated, finding the tach stinks.

The install manual is confusing about this part.  Nowhere does it say it offers voltage sensing.  But then in the programable options list it shows

Input check......  voltage or Tach

Voltage level......   >0.5V B4 start or <0.5v B4 start

Now reading that would lead me to believe it does offer voltage sense.  I am installing an Audiovox Prestige AS 9076 remote start upgrade module.  I'd be curious to see if anyone can tell me exactly what type of signal the audiovox unit is looking to see on the tach input wire.  Is it a pulsed positive or pulsed negative?  If you're gonna tell me it's an AC signal, then why is it.

Yea, I saw that post.  There looks to be some conflicting information in that post.  In the beginning when he's talking about an old style coil and distributor setup ronco says......

"So merely running a wire to the "hot side" of the coil primary ( the other connection on the coil is typically tied to ground) and we have the "tach signal" for the RS system."

Then later down the post ronco says......

"Basically, each injector solenoid has 2 wires. One wire is "common" ( the same color at each solenoid) and is tied to +12V through usually a 20 amp fuse labeled  INJ/COIL in the fuse panel. Each individual other wire on each solenoid goes through the harness and back to the computer which switches (pulses) that wire to ground to activate the injector at a frequency proportional to engine RPM . So all you need to do is tie on to one of these wires ( identified by the service manual) and bingo, there's your "tach signal".

First ronco says to hook to a positve in the distributor style but hook to a negative in the fuel injector example.  I believe the correct way on a distributor ignition is to hook up to the negative wire on the coil.  This is the wire that is make and break by the distributor.  The positive lead on the coil is hot all the time.  See here.......  http://www.familycar.com/Classroom/ignition.htm  also read this post for more interesting info........ http://www.physicsforums.com/showthread.php?t=40278  read farther down the post to get to the point.